that s the mosque we used to pray in, yes, yes. reporter: five times every day, devout muslims turn towards the holy city of mecca to pray. osama was always among them. for him it was a must. reporter: it is something of a mystery, why this son of a wealthy family was drawn to such rigid religious beliefs. over time batarfi saw his best friend become even more of a fundamentalist, striving to live according to his ultrastrict interpretation of the holy koran. no pictures, no music, and after that, not even tv. unless there s news. reporter: osama s religious devotion went beyond living a simple pious life.
he had begun to believe it was his duty to prepare to one day fight for and defend islam. osama s training ground, the desolate saudi desert. the son of a multimillionaire was now preparing for a life without luxuries or even basic essentials, a life as a holy warrior. i hear from his brothers that when they go there, they sleep on the sand. there s no blanket if it s cold, and they, you know like soldiers. reporter: batarfi had no desire to join osama s army, so the two friends began to drift apart. i would prefer the beach. i was more romantic. you know, i was thinking of love. he was thinking of love of god. reporter: but how did osama
this riyadh neighborhood. he was the only child his mother had with mohammed bin laden before they divorced. then, bin laden and his mother, aliyah, moved to jeddah and lived here, apart from the other wives and children. mohammed bin laden died when osama was just 10 years old. the school was abuzz with the news that mohammed bin laden had been killed in a plane crash. reporter: with so many siblings, it s hard to say how close osama was to his father or how the loss affected him. this photograph from the early 1970s shows some of the many bin laden brothers and sisters on a vacation in sweden. osama was quiet and shy. his teacher says he rarely spoke up in class. he didn t show any particular signs of being a leader amongst men. he was a shy boy.
the boys had a western uniform. they had trousers and shirts and jackets and shoes. faifel shaler had taught a number of bin laden s brothers. osama s family was well-known in saudi arabia. his father s career was the stuff of legend. the bin ladens were almost a storybook success. reporter: in saudi arabia, the bin laden name is everywhere. it s a vast empire with humble beginnings. the family patriarch, mohammed, seen here in rare photographs, rose from a menial laborer to head one of the largest and most successful construction companies in the middle east. he built the airport. he built virtually everything that was standing more than two meters high had been built by bin laden. reporter: he had more than 50 children. osama was born in 1957, here in
batarfi was the leader. osama, the follower. but i would tell him what to do, and he was a good soldier. he would follow orders. usually because he was taller than most of us and older, he would play in the front, because this way he could use his head to, you know, score. reporter: batarfi says the teenage osama would usually take the high road. he remembers a time his friend was being bullied. so i went running to the guy, and i pushed him away from osama and solved the problem this way, but then osama came to me and said, you know, if you would have waited a few minutes, i would have solved the problem peacefully. so this was the kind of guy who would always think of solving problems peacefully. reporter: while batarfi took the lead on the playing field, when it came to religion, there was no question, osama was in charge.